Study of Potential Plant Growth-Promoting Activities and Heavy Metal Tolerance of Pseudomonas aeruginosa HMR16 Isolated from Zawar, Udaipur, India

The use of plant growth-promoting rhizobacteria (PGPR) is steadily increasing in agriculture and offers an attractive way to replace chemical fertilizers, pesticides, and supplements. Genus Pseudomonas is widespread bacteria in agricultural soils and has many traits that make them well-matched as PGPR. Pseudomonas aeruginosa HMR16 isolated from heavy metal contaminated soil of Zawar, Udaipur was tested for direct plant growth promoting activities (IAA production, production of ammonia and phosphate solubilization) and indirect growth promoting activities (HCN production, siderophore production). Effect of heavy metals such as zinc, lead, chromium on growth of Pseudomonas aeruginosa HMR16 was also determined on nutrient agar and nutrient broth medium supplemented with respective heavy metals concentrations. Pseudomonas aeruginosa HMR16 was found to be positive for the production of plant growth-promoting hormone (IAA), ammonia, HCN, siderophores and solublize phosphate with solubilization efficiency of 115.38. Minimum inhibitory concentration (MIC) of zinc, lead, and chromium against Pseudomonas aeruginosa HMR16 strains were 16.0mM, 1.25 mM and 0.30mM respectively. Pseudomonas aeruginosa HMR16 showed various plant growth promoting activities and tolerance to heavy metals thus it can be used to improve plant growth in heavy metal contaminated soil.